Hi everyone,

I have been thinking about swapping my driver side 2 way power seat to a memory seat for a while.
So I picked up a driver side memory seat plus the door panel with memory switch and the blue wire for a decent price today. I did not grab the wires from under the driver seat carpet as they were already been cut off from the connectors. There is a black control box under the memory seat and one of the connector is different from my original connector from under the driver seat carpet.

The first picture is the memory seat and the second picture is my original 2 way power seat, as you can see # 3 connectors are different but #1 and #2 connectors should be plug n play.


Memory seat


Non-memory power seat


The connector which plugs into the Non-Memory seat switch is 12 pins whereas the #3 connector from Memory seat is 14 pins.


Anyone had tried to retrofit the memory seat and actually figure out how to make it work?

 

There are two output connector #3 and #4 form the back of the control box for the memory seat whereas there is only one output connector # for the 2way power seat.
Other than that, the two motors and its plugged wires from these two seats are identical.


Memory seat


2way power seat



Anyone knows what I missed or how to make the memory function to work?

 

As we discussed in our private messages, I decided not to attempt to use the memory seat function when I swapped some C63 AMG seats into my W203 C230. C63 seats in a W203

Here's what I can tell you based on my experience:
1. The yellow connector is for the air bags. It looks like this will be "plug and play" for you.
2. The long black connector with two wires is for the seat heaters - again this should be "plug and play."

Now for the hard part - the memory control. Here I am just providing some suggestions based on very limited experience tampering with my seats, but I did not attempt to make the memory function of my C63 seats work. There were just too many differences between the W204 and W203 and I would have been required to buy two door panels with memory controls before I could even begin to figure it out.

First, the memory seats have more seat motors than the non-memory "two-way power" seats. The two way seats have two motors - One to tilt the seat back and one to tilt the front of the seat bottom cushion. On the memory seats in the C63 I had three motors. The additional motor moved the entire seat fore and aft.

In post 8 of my C63 seat thread, I discuss the large wiring harnesses in the C63 seat. Note that there are 12 pins assigned in the large white connector (connector #3 in your fourth photo) and two are empty. In the two-way power seats, two wires connect to each motor. On the C63 seats (and I think the same is true for your memory seats) four wires go to each motor. That explains the twelve wires (3 motors X 4 wires each.) The reason there are four wires connected to each motor is that one circuit with two wires is for the manual input from the door controls and the second circuit with two wires is for input from the memory. Fortunately, you don't need to do anything with this.

By the process of elimination, I conclude that the black 6-pin connector (connector #4 in your fourth photo) may be for inputs from the seat controls on the door. Check to see where the wires from the black connector go. If they connect to the front of the seat (connector #2 in your first photo) that strongly suggests that they accept the input from your door controller.

Please post what you find out.

 

@snap Did you ever make this work?

I am in the same situation as you.

Has ANYONE made this work or does anyone know if it is possible??

 

This thread shows details for retrofitting memory seats in a W203.

I retrofitted W204 (C63 AMG) seats in my W203. Another board member figured out how to add the memory function and I was able to use his work as a model for completing the same upgrade in my car.

It looks like the operation and components of the seats in W204's and W203's are similar. If you can find a W204 with memory seats in a "pick and pull" lot, you should be able to harvest the parts you need and determine the process for installing memory seats in your car.

Good luck with your project.

 

@KevinH2000 So i read your thread. Nice job!
Very kind of you to share all the details!
Sometimes i think the modding commmunity for mercedes is very closed unfortunately....

Must have taken a hell of a time
So from what i can read in your thread it seems like "connector 3" in the picture below, i actually only need to have CAN HIGH, CAN LOW, and POWER?
And then we should be good to go?

I can see the door modules for the W204 should be the same with and without memory, there should be a connector for the seat memory buttons.

Now the question is, since i am not swapping from a different model like you, maybe the wiring will be easier for me, but of course you can never be sure.

Maybe another option would be to find the harness from a memory donor car, and see if that can be swapped plug and play, but who knows....

 

I had to review the thread to see what I had done since it has been almost 4 years since I worked on this project. It looks like I needed to add four wires to each seat:
1. Power
2. Ground
3. CAN High
4 CAN Low

The key to figuring this out is to study the donor car for clues to how Mercedes wired the memory function. I found that there were several wires attached to the seat connector that I didn't connect.

In response to your comment, "I can see the door modules for the W204 should be the same with and without memory, there should be a connector for the seat memory buttons," - please check post #28 of the thread that I linked. While the module in my driver's door worked with my memory seats, I needed a different module in the passenger's door. My specific W203 model (a 2005 C230) was not available from the factory with a passenger memory seat. Only a driver's side memory seat was available. More expensive models like the C240 and the C320 were available with passenger seat memory. My guess is that Mercedes was able to save a few dollars (euros) by installing a less expensive module in the passenger door of the C230's. If you happen to run across a W204 with memory seats, I suggest that you scavenge the door modules from both doors in the event that you need them.

You may also want to review my work using the Mercedes Star system to activate the "Easy Exit" function. I don't know whether the W204 has the same function, but it is kind of neat.

Finally, you may want to grab the outside door mirrors if you see them on a donor car. I recently had a minor mishap in a parking garage that required replacement of my passenger side mirror. (I parked too close to a pillar and damaged the mirror when I backed out of the space.) The used replacement mirror I purchased had memory and when I plugged it into the system, it worked.

 

@shih1919 Didn't you make this modification, retro fitting fully automatic seats to a smi automatic W204?

 

I fit fully automatic W204 seats to a W203 with semi-automatic seats. The seats I replaced had powered backrest and seat bottom tilt controls. The replacement seats (from a C63 AMG) have powered fore and aft adjustment, backrest tilt and seat bottom adjustments. They also have powered lumbar supports and powered seat back side bolsters. This thread shows the details about the seats I installed. It is a long thread because it took me over a year to figure out how to make the seats work in my car.

One point that I remember from my research is that some people had attempted to install C63 seats into a non-AMG W204. The issue they encountered was that because the non-AMG cars had adjustable head rests, there was some type of headrest adjustment mechanism that activated during a crash. Because the AMG seats have integrated headrests, the standard W204 cars would generate an SRS (supplemental restraint system) error when they installed the C63 seats. I don't know whether anyone solved this problem.

 

@KevinH2000 So i bought the seats today, and are getting them in one week.

I do have a question so i can prepare myself on how to connect them. The door modules included from the donor car also.

Now i have some questions i would hope you can help me answer:

1. How can i order the 14-Pin connector so i can do the reqiring, does it have a part no or name so i can buy it from mercedes?
2. How exactly do i connect the new 14-Pin Connector to the CAN B, and do i need to order any connectors for this?
3. If i have read threads correctly i have to change the power supply in the rear sam so it doesen't provide constant power but stops some minutes after ignition is off. How is this done? By coding or rewiring, and if rewiring, how exactly?

I really hope you would take the time to look at the questions as it would be the most helpful thing!

 

1. How can i order the 14-Pin connector so i can do the reqiring, does it have a part no or name so i can buy it from mercedes?

I may have a couple of W204 connectors. If I recall correctly, Saabatour (the board member who installed C63 seats in his C55) sent them to me, but I didn't need them. I'll check my parts box this weekend. If I can find them, you can have them for the cost of shipping. I'll send you a personal message asking for your address. If I have the connectors they will be "pigtails." That is, they will consist of the connector and a few inches of wire connected to each pin. You can solder additional lengths of wire to each wire on the connector to make longer runs.
Look at post #17 in this thread. There is a picture of the pigtails that I may still have.

2. How exactly do i connect the new 14-Pin Connector to the CAN B, and do i need to order any connectors for this?

In my car, there is a CAN Block under the steering wheel. (You need to remove the trim panel to see it.) On my car, that CAN Block had several empty slots, and I inserted my connectors (one for each seat) into it. Here's a picture of the CAN Block in my car:


I suggest you search this forum using the term "CAN Block" and see whether any other members have added posted information specific to the W204. I found it very helpful to scavenge a parts car and collect wiring and connectors. It also provided me an opportunity to learn how to access and remove components without risking damage to my car.

3. If i have read threads correctly i have to change the power supply in the rear sam so it doesen't provide constant power but stops some minutes after ignition is off. How is this done? By coding or rewiring, and if rewiring, how exactly?

I didn't have to do this on my car. On early W203's, there was a power drain associated with the power seats. (I have a later W203 with a redesigned power seat module and haven't experienced the problem.) The way the owners of early W203's solved the problem is shown in this video:

 

@KevinH2000 All right.
I found the connector part no, just FYI for others also interested it is:
A 220 545 3728

Can get it for 3 dollars at my local mercedes dealer, super nice.
i have 2 road bumps right now

1.
The pin contacts (i think it's called that in English, in danish "stikben". The little fella you squeeze around the wire, and then you can push the pin and wire into the connector)
These are very expensive at my local dealer, 3 bucks a piece. 2x 10 of them if i want to connect an electrical steering wheel column is 75 bucks just for pin contacts. The dealer would send me the part no. he was very kind, and loved my project, so maybe i can find these more cheap another place, or buy some generic ones with the same measurements.

2. The pin contacts for the Can Hub and the connectors itself to push into the can hub. I don't have part no. for those yet, even though the guy at the dealer promised me to find them and return, so i guess i have to wait a couple of days.

But! if everything goes well i will buy the connectors, pin contacts and necessary wires next week and try to fit everything together next weekend.

 

@KevinH2000 Made it work!
I have made a tutorial here!!!
https://mbworld.org/forums/c-class-w...ml#post9124770